Engine mounts are in general no longer available, but "new old stock" sometimes appears on eBay (check Europe, not just the UK). But also check with Joe (FCSS aka Countrycruising on here) since he manged to get hold of some recently IIRC.
Vibratechnics do "road" and "race" versions by the way.
2000 Pearl White Plus & 1996 Portofino 20vt
1985 & 2016 2017 Fiat 124 Spider + XF Sportbrake